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Why biophysics works for me

Five scientists talk to Jon Cartwright about why they are drawn to problems on the border between biology and physics.

People go into biophysics for a variety of motivations, but if one reason stands out, it is this: it focuses on phenomena that are familiar to all of us. While some topics in physics can seem esoteric and far removed from everyday life, biophysics can be more personal. How does a cell work, for example, or what is the molecular basis of AIDS? These are questions to which everyone can relate.

Yet perhaps biophysics is also attractive to scientists because it is fairly new, and draws from many other disciplines. You might have trained as a nuclear physicist, a computer programmer or a physical chemist and still have much to offer. Here, five scientists with interests in biophysics – all with very different backgrounds – reveal what they enjoy about their subject.

Deborah FygensonAssociate professor at the University of California, Santa Barbara, USDeborah Fygenson studied atomic physics as an undergraduate at the Massachusetts Institute of Technology, and intended to focus on condensed-matter physics for her PhD at Princeton University. However, by the time it came to choosing a thesis topic she had become distracted by one of the university's new professors, Albert Libchaber – a veteran researcher in the physics of turbulence. However, it was not turbulence that Libchaber was promoting. "He was very clear that physics was dead, and biology was the future," says Fygenson. "The way he presented it was quite exciting – that there are physical phenomena within biology that the tools of molecular biology had made accessible to harder science, to physics-type studies."

In her current research, Fygenson is using cutting-edge tools such as DNA origami – a method of folding genetic material into 2D and 3D shapes – to work out how to recreate some of the nanostructures seen in biology. She hopes to learn why cells are built the way they are, and in the process discover how to build different nanostructures that might find uses in bioengineering.

For Fygenson, it is the "immediacy" of biophysics that makes the subject so attractive. "It's the potential for impact on human life, the phenomena being close by," she says. "I think that if we start to better understand the physical limitations imposed by biomaterials, we'll have fundamental insights into why biology is constructed the way it is."

Julian MogerSenior lecturer at the University of Exeter, UKThe blood–brain barrier – a filtering mechanism that exists between the brain and its blood-supplying capillaries – is crucial for keeping our brains free from dangerous microscopic particles, such as bacteria. Unfortunately, the filtering mechanism is so effective that, if someone does get a brain infection, it is often incredibly difficult for vital drugs to make it through the barrier. Julian Moger is improving techniques that help pharmacists visualize the blood–brain barrier so that they can develop drugs that are more effective at penetrating it. "My input is to provide techniques that give them information to rationally engineer particles to do this better," he says. "So it's giving them some feedback as to how their strategies are actually working."

Moger began academic life with an undergraduate physics degree at Exeter, which led him to a PhD in optical coherence tomography, a postdoc in Raman spectroscopy and finally a lectureship in applied photonics. Today, his favourite aspect of research is getting results he does not understand – something Moger views as a challenge to figure out what is really happening. "People think of biology as being well understood, but it's probably one of the most exciting areas of scientific research," he says. "We still don't really understand what makes the body work. It's just a fascinating machine. I am really enjoying developing techniques that allow us to understand how we work, and where life comes from."

Stephanie AllenAssociate professor at the University of Nottingham, UKStephanie Allen knew she wanted to be a scientist for a long time. Her father was a chemist, and while studying for her A-levels she remembers reading science magazines about the latest developments such as the scanning tunnelling microscope and, later, the atomic force microscope. But for her undergraduate degree she read pharmacy, and it was only when she looked at PhD options that the field of biophysics stood out. "A new lab had opened up in the School of Pharmacy where I studied," she says. "I thought it was really cool that you could image single biological molecules – it was a really interesting area, a really new area."

Today, Allen's work focuses on understanding the structure, function and interactions of single biological molecules. One of her projects seeks to understand how proteins bind to DNA inside bacteria during the DNA replication process. "If you can understand the process of DNA replication, and related processes that enable genes to be switched on and off, you may reveal potential new targets for the development of therapeutic antibiotics," she says.

Elspeth GarmanProfessor at the University of Oxford and president of the British Crystallographic AssociationElspeth Garman, one of the UK's leading biophysicists, gives a frank reason for why she enjoys biophysics so much. "I can explain to someone I meet on the bus or a taxi driver what I do," she says. "It has an immediately understandable impact."

Garman earned a PhD in low-energy nuclear-structure experimental physics in 1980, after which she continued her research and tutored at the University of Oxford's Somerville College. After seven years, however, she found that funding for nuclear physics was drying up. Looking for a new field, she was persuaded to veer towards biology by the UK biophysicist Louise Johnson. Today, one of Garman's major interests is studying radiation damage in biological samples examined with X-rays. By understanding how X-rays affect samples, she can learn how to separate true observed features from those created by the X-rays used to image them.

Garman is also director of the Life Sciences Interface Doctoral Training Centre at Oxford, which encourages physics, engineering and maths graduates to do a six-month crash course in biology so that they can go on to do biophysics at PhD level. "I think that physics has a huge amount to offer biology, and there are several reasons for that," she explains. "One is that physics techniques such as microscopy have advanced so far now that we can look at real problems. Instead of being reductionist physicists where we chop up everything to the nearest quark, we can start to ask, how does a whole cell work? Or at least, how does this protein complex work?"

Thomas KraussHead of the School of Physics and Astronomy, University of St Andrews, UKThomas Krauss is a great example of biophysics' interdisciplinary nature. An engineer by training, he spent his early career developing photonics for Internet applications. But when the dot-com bubble burst at the turn of the millennium, Krauss began to look for other areas where he could apply his technological insights. "What ultimately drives me is that I want to do something good. And pushing Internet capacity – it is basically driven by porn downloads," he jokes. "In biophysics I see far more interesting questions to ask."

Although biophysics is still "not his main breadwinner", Krauss has several interests in the field. One is creating ultra-small biological sensing devices using photonics, which could have applications such as monitoring blood-oxygen levels in a living organism. Another is the nascent field of "optogenetics" – a process that makes certain nerve cells light-sensitive by infecting them with a virus, so that biologists can learn how they transmit signals at a cellular level. "Combining optogenetics with my interest of controlling light at the nanoscale, you can imagine an array of light emitters firing at neurons, controlling their function at an array type of scale," explains Krauss.

"I was starting to get bored of telecoms," he adds. "When you do something for 10 years, you start to know most of it. Of course, you never know everything, but the factor of learning gets smaller and smaller. Whereas in biophysics there is so much I have yet to learn."